Light emitting diode package

ABSTRACT

Provided is an LED package. It is easy to control luminance according to the luminance and an angle applicable. Since heat is efficiently emitted, the LED package is easily applicable to a high luminance LED. The manufacturing process is convenient and the cost is reduced. The LED package includes a substrate, an electrode, an LED, and a heatsink hole. The electrode is formed on the substrate. The LED is mounted in a side of the substrate and is electrically connected to the electrode. The heatsink hole is formed to pass through the substrate, for emitting out heat generated from the LED.

This application is a continuation of application Ser. No. 12/552,911,filed on Sep. 2, 2009 now U.S. Pat. No. 7,989,835, which is acontinuation of application Ser. No. 11/583,043, filed on Oct. 19, 2006now U.S. Pat. No. 7,592,638, for which priority is claimed under 35U.S.C. §120, and this application claims priority of Application No.10-2005-0098594, filed in the Republic of Korea on Oct. 19, 2005 under35 U.S.C. §119; the entire contents of all are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting diode and a package ofa light emitting diode.

2. Description of the Related Art

A light emitting diode (LED) is a light emitting device constituting alight source by using compound semiconductor materials such as GaAs,AlGaAs, GaN, InGaN, and AlGaInP. The LED has the advantage of emittingvarious colors on materials of the semiconductor.

Generally, the characteristics of the LED are determined according tohigh-luminance light-emitting, luminance, color range of the emittedlight, and the like. The characteristics of the LED device are primarydetermined by the compound semiconductor materials used in the LEDdevice. Also, the characteristics are secondly determined by packageconstruction for mounting a chip. Especially, in order to obtaindistribution of a luminance angle according to high luminance and userrequirements, the primary element of the materials is limited. So,recently, many people are interested in the package construction.

The second element of the LED package construction largely affects theluminance and the high-luminance light-emitting. Referring to aconventional package illustrated in FIGS. 1A through 1C, a lamp type LEDand a surface mounted type LED will be described, separately.

For a lamp type LED package 10 illustrated in FIG. 1A, a metal electrodeface of a cup shape with a predetermined angle is provided on the upperside of a lead frame 3B among two lead frames 3A, 3B. An LED device 5 ismounted on the upper side of the metal electrode face. Also, the lamptype LED 10 is packaged by a domed case 7 which is made of transparentmolding resin.

On the other hand, as illustrated in FIG. 1B, a surface mounted type LEDpackage 20 has a package 11 which is made of molding epoxy resin. Also,an LED device 15 is arranged on a mounting region where an inclinedangle is small, and an electrode (not shown) is connected by a wire 13.

By such package construction, in the lamp type LED package 10, the domedcase 7 working as a lens, can control the luminance. Especially, bymaking the distribution of the luminance angle narrow, the luminance ata predetermined luminance angle can be raised. Also, light which isemitted from a source is reflected on the metal electrode face of thecup shape to raise the luminance. When comparing with the lamp type LEDpackage 10, in the surface mounted type LED package 20, distribution ofthe luminance angle is made wide by the package 11, and the luminanceitself is low. In this manner, the luminance and the distribution of theluminance are largely affected by the package construction. Therefore,in the case of the surface mounted type LED package 20 using moldingresin, a development to add a reflecting member is being processed. Thereflecting member is a metalized construction having a predeterminedreflecting angle and formed at one side of the mounting region.

However, since the construction of the LED package using the moldingresin does not have high enough thermal resistance for heat generated byhigh luminance light, the LED package is not appropriate for thehigh-luminance emitting-light.

FIG. 1C is a sectional view illustrating a ceramic LED package which ismade of a conventional ceramic substrate.

Referring to FIG. 1C, a construction 30 of the ceramic LED package hastwo ceramic substrates 21 and 22. Each the ceramic substrate has aplurality of ceramic sheets which are laminated. Mounting region for anLED device 25 is located on a lower ceramic substrate 21. An electrode23 which is connected to the LED device 25 by a wire 27 is extended,through both sides of the ceramic substrates, from the mounting regionto the bottom of the substrate. An upper ceramic substrate 22 having apredetermined cavity surrounds the mounting region for the LED device25.

Here, since the cavity for the mounting region receiving the LED device25 is formed by punching or cutting, a cutting face is vertically formedat all times as illustrated in FIG. 1C. Therefore, it is difficult toform a reflecting face which can control the luminance angle by making apredetermined inclined plane inside of the cavity. In addition, it makesa manufacturing process complicated and increases the cost that theceramic substrate 22 supplying the cavity is made of the plurality ofsubstrates which are laminated.

Also, since the heat which is generated by the high luminance light isemitted through only the electrode 23, emitting heat is not rapid, whichhas a bad influence on characteristics of operation of the LED device25. Therefore, an LED package which can efficiently emit heat in aceramic package has been strongly required.

In addition, it takes manufacturing time longer and increase the cost,because the ceramic substrate 22 is made of the plurality of substrateswhich are laminated.

SUMMARY OF THE INVENTION

Accordingly, the present invention is related to a light emitting diodepackage that substantially obviates one or more problems due tolimitations and disadvantages of the related art.

The embodiment of the present invention provides an LED packagecomprising: a substrate, an electrode or more formed in the substrate,an LED mounted on a side of the substrate and electrically connected tothe electrode, and at least one heatsink hole formed to pass through thesubstrate, for emitting heat generated from the LED to the outside.

The embodiment of the present invention provides an LED packagecomprising: a substrate, an electrode or more formed in the substrate,an LED mounted on one side of the substrate and electrically connectedto the electrode, a heatsink portion formed in the substrate, foremitting out heat generated from the LED, and a reflecting member formedaround the LED, for reflecting light emitted from the LED, thereflecting member being injection molded.

The embodiment of the present invention provides an LED packagecomprising: a substrate, an LED mounted on one side of the substrate,for emitting light using an external power, at least one heatsink holeformed in a portion of the substrate that is aligned with the LED, foremitting out heat generated from the LED, and a reflecting member formedof a resin and separately coupled on the substrate around LED, forreflecting light emitted from the LED.

The embodiment of the present invention provides an LED packagecomprising: a substrate, an LED mounted on one side of the substrate,for emitting light using an external power, a plurality of heatsinkholes each having a diameter of about 50-100 μm and formed in at least aportion of the substrate that is aligned with the LED, for emitting outheat generated from the LED, and a reflecting member formed of a resinand formed outside the LED, for reflecting light emitted from the LED.

For the LED package of the embodiment of the invention, it is easy tocontrol luminance according to the luminance and an angle. Since heat isefficiently emitted, the LED package is easily applicable to a highluminance LED. Also, by manufacturing the LED package with a simpleconstruction, the manufacturing process is convenient and the cost islow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A through 1C are conventional constructions of an LED package,wherein FIG. 1A is a sectional view illustrating an lamp type LEDpackage, FIG. 1B is a sectional view illustrating a surface mounted typeLED package, and FIG. 1C is a sectional view illustrating a ceramic LEDpackage;

FIG. 2 is a sectional view illustrating an LED package according to thepresent invention;

FIG. 3 is a plan view illustrating the LED package according to thepresent invention;

FIG. 4 is a plan view illustrating a reflecting member in an LED packageaccording to another embodiment of the present invention; and

FIG. 5 is a sectional view illustrating a package describing theembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 2 is a sectional view illustrating an LED package 200 according tothe present invention.

Referring to FIG. 2, the LED package 200 of the present inventionincludes a ceramic substrate 240, an LED 210 mounted on the upper sideof the ceramic substrate 240, a reflecting member 220 formed around theportion in which the LED 210 is mounted, an electrode 260 and 261 andwire 230 and 231 provided on the upper side of the ceramic substrate 240and electrically connected to the LED 210, and a heat sink 270 and aheatsink hole 280 emitting out heat generated from the LED 210.

In detail, since the ceramic substrate 240 is provided as a singlelayer, it is possible to reduce the manufacturing process and take themanufacturing time shorter.

Also, it is advantageous for the improvement of luminance and thecontrol of a luminance angle that the reflecting member 220 is providedsurrounding all around the LED 210. In detail, the reflecting member 220may be made of polypropylene (PP) having a high reflectance coating andthe inner surface may be cylindrical as illustrated in FIG. 3. Further,the shape of the inner surface of the reflecting member 220 is that theupper diameter may be larger than the lower diameter. The reason isbecause, although it achieves some increase in luminance to insert thereflecting member 220 which is formed as a cylindrical type into themounting region, it may increase the luminance of the entire light aswell as the luminance of upward light to control the difference of thediameters by making the lower diameter be smaller than the upperdiameter.

The reflecting member 220 can be easily made by such as a PP injectionmolding. A metal layer (not shown) such as Al, Ag is formed on the innersurface of the reflecting member 220 for reflection. Also, a pluralityof protruding contact portions 250 may be provided on the lower side ofthe reflecting member 220 in order to be bonded to the ceramic substrate240. The protruding contact portions 250 not only guide the reflectingmember 220 for bonding to an appropriate position of the ceramicsubstrate 240 but also strengthen the bonding between the ceramicsubstrate 240 and the reflecting member 220.

Also, the electrode 260 and 261 is provided for the electricalconduction and the thermal conduction, wherein the electrode 260 isextended to the bottom through the side of the ceramic substrate 240 andsupplies a run current to the LED 210 through the wire 230 and 231 asillustrated in FIG. 3. By the electrode 260 which is provided further tothe bottom of the LED 210, heat generated from the LED 210 is morerapidly transmitted downward to be emitted downward through the heatsinkhole 280 or be emitted into the side along the electrode 260 itself As amatter of course, when the electrode 260 does not work like this, theelectrode 260 is provided not as a plate type but as a wire type on theceramic substrate 240 and just conducts electricity.

The heat sink 270 is provided on the bottom of the ceramic substrate240, facing the LED 210 and having a predetermined shape, for example, acircular type or a tetragonal type, and contacts the heatsink hole 280to emit the heat of the LED transmitted through the heatsink hole 280.

The heatsink hole 280 has a plurality of holes having the diameter ofabout 50-100 μm in the ceramic substrate 240. A metal material, forexample, Ag is filled in the heatsink hole 280 by electroplating or ametal deposition. The heat sink 270 is united with the heatsink hole280. Since the filler in the heatsink hole 280 has high thermalconductivity, it is apparent that a great quantity of heat is morerapidly transmitted through the heatsink hole 280.

The process of the configuration of the LED package 200 will bedescribed in the following in more detail.

First, the plurality of heatsink holes 280 are formed in the ceramicsubstrate 240 which is made of a single layer by a mechanical method orchemical etching. Also, Ag is filled in the heatsink holes 280 byelectroplating or a metal deposition.

After filling Ag in the heatsink holes 280, the electrode 260 and theheat sink 270 are formed in order to cover all the heatsink holes 280and the LED 210 is mounted on a predetermined position of the electrode260. Subsequently, the wire 230 and 231 is formed in order to beconnected to the LED 210 and the electrode 260 and 261, respectively.

The reflecting member 220 is bonded to the ceramic substrate 240 by theplurality of protruding contact portions 250 and a silicon based bondingmaterial, to surround the mounting region of the LED 210. As a matter ofcourse, for the protruding contact portions 250 by being just fittedinto the ceramic substrate 240, the reflecting member 220 may be bondedor by only a bonding material without the protruding contact portions250, the reflecting member 220 may be bonded. However, it improves thebonding strength and the workability to bond around the protrudingcontact portions 250 after the reflecting member 220 is guided by theprotruding contact portions 250. Here, the reflecting member 220 whichis bonded may be the tetragonal type illustrated in FIG. 4 as well asthe circular type illustrated in FIG. 3.

In addition, since the reflecting member 220 is simply bonded to thesingle layer ceramic package, the manufacturing process of the ceramicpackage becomes simple and the characteristics of the luminance can beimproved through the material of the reflecting member 220 and thereflectance coating.

After the reflecting member 220 is bonded, on the upper side of the LED210, namely on a cavity formed inside the reflecting member 220, amolding lens (not shown) can be further formed by filling a transparentepoxy resin or a silicon based resin.

FIG. 5 is a sectional view illustrating a package describing anotherembodiment of the present invention. When compared with FIG. 2, onlyparts which are characteristically different are described and theothers follow the descriptions in the precedent embodiment.

Referring to FIG. 5, a lens placing part 301 for placing a lens 300 isfurther formed in a reflecting member 220. The prepared lens 300 isplaced on the lens placing part 301. This type is more convenient forattaching the lens 300. The reason is because the reflecting member 220,as a single part, is previously prepared by injection molding to easilyprovide the lens placing part 301, that the lens 300 is convenientlyplaced.

According to other embodiment, by further forming an additionalsupporting member in the reflecting member 220, when a mold material isfilled in a cavity provided in the reflecting member 220, the moldmaterial and the reflecting member 220 can be more strongly supported.

According to still other embodiment, although metal may be filled in theheatsink holes, it is possible to emit thermal by only air, without afiller.

According to the present invention as described above, the followingIndustrial applicability and advantageous effect can be obtained. First,it makes the manufacturing process of the LED package more simple, andmakes the shape of the reflecting member 220 more appropriate andpreferable that the reflecting member 220 is bonded on the ceramicsubstrate 240 by the bonding material after the reflecting member 220 ismade by an additional process such as the injection molding. Forexample, for the inner shape of the reflecting member 220, the inclinedangle of the inclined plane is more variously controlled and theinclined plane may be formed to have a direction. That is, the innershape of the reflecting member 220 is various on the shape that userwants.

According to the present invention, under the construction of the LEDpackage 200, since heat generated from the LED 210 is transmitted to theelectrode 260, the heatsink holes 280, and the heat sink 270 to beemitted, the problems in the thermal stress and the degradation of anLED device which are caused by heat can be solved. Therefore, since theheat generated from the LED 210 is emitted downward at minimum distancethrough the heatsink holes 280 provided in the mounting region of theLED 210, the reliability of the LED 210 can be guaranteed. Further,since the heat is emitted along the electrode 260, the heat emittingefficiency is more improved. Therefore, a high luminance LED can be alsostably supported without the degradation, and the reliability of thehigh luminance LED package is improved.

In addition, since the reflecting member 220 is simply bonded to thesingle layer ceramic substrate 240, the manufacturing process of theceramic package becomes simple.

Also, since the ceramic substrate 240 is a single layer, it does nothave to be laminated. Therefore, the manufacturing process becomes moresimple.

In addition, since the reflecting member 220 is made of not aconventional metal material but a PP material, the weight of the ceramicpackage can be reduced. Since the reflecting member 220 is made by aresin injection molding, the construction of the reflecting member 220is various and is made conveniently on the shape that user wants.

What is claimed is:
 1. A light emitting diode package comprising: aplanar substrate; a light emitting diode disposed on the substrate; afirst metal layer disposed on the top surface of the substrate; a secondmetal layer disposed on the top surface of the substrate, the secondmetal layer being separated from and not contacting the first metallayer; a third metal layer disposed on a bottom surface of the substrateand functioning as an anode for the light emitting diode, the thirdmetal layer being connected to one of the first and second metal layers;a fourth metal layer disposed on the bottom of the substrate andfunctioning as a cathode for the light emitting diode, the fourth metallayer being connected to the other one of the first and second metallayers; a fifth metal layer disposed on the bottom of the substrate andfunctioning as a thermal pad for dissipating heat from the lightemitting, diode; at least two through-holes passing through thesubstrate, and being formed at a position that is not on a central axisof the light emitting diode and is spaced away from and outside of thelight emitting diode; and a reflecting layer disposed on the first andsecond metal layers, the reflecting layer being coated with a reflectivematerial, wherein a sidewall of the at least two through-holes is madeof a metal material.
 2. The light emitting diode package of claim 1,wherein the reflecting layer is made of a different material than amaterial of the substrate.
 3. The light emitting diode package of claim1, further comprising: a lens placed on the light emitting diode.
 4. Thelight emitting diode package of claim 1, wherein a material of thesubstrate is a ceramic material.
 5. The light emitting diode package ofclaim 1, further comprising a plurality of through-holes formed underthe light emitting diode.
 6. The light emitting diode package of claim5, wherein the fifth metal layer is connected to the light emittingdiode via one of the plurality of through-holes.
 7. The light emittingdiode package of claim 5, wherein the plurality of through-holes havebilateral symmetry.